Date   : Sat, 05 Feb 2005 00:53:02 GMT
From   : Pete Turnbull <pete@...>
Subject: Re: bbc lockups

On Feb 4 2005, 18:50, Tim Fardell wrote:
> An "Air Duster" spray is also good for this. It's an ordinary spray
can that
> squirts out a jet of air[1] to remove dust from components etc. Most
> electronics shops sell it.

That's OK for small amounts of dust, or getting into awkward areas, but
a vacuum is better for many things, or anywhere there's lots of dust,
biscuit crumbs, hair, ...  Do you really want to blow all that crud
into the air you're breathing?  Or into the crevices under the
components?  If you have real classics, don't use compressed or canned
air on core memory, for example.  Andy's tip about using a paint brush
and not touching the nozzle to the board is a good one, and another
trick is to wrap some aluminium foil around the nozzle, and ground it.
 You can also get conductive nozzles and even ones that have antistatic
brushes, but I'd not bother unless you do this sort of thing regularly
(which I do).

Someone suggested using contact cleaner.  Don't.  It's for switches,
not socketed chips.  It will make matters worse in the long run.  And
don't even think about WD40, which should be banned from the vicinty of
computers.  If a board is really mucky, wash it in lukewarm water with
a little detergent (wetting agent, helps it drain), drain off the
water, blow out with low-pressure compressed air if it helps and/or
rinse with iso-propyl alcohol (removes most of the water) and dry
thoroughly.  Protect any labels and unsealed relays before washing.
 Extreme cases, or larger numbers of boards, may benefit from a cycle
through the dishwasher, but avoid the hot drying cycle (that's pretty
close to what's done commercially).


-- 
Pete						Peter Turnbull
						Network Manager
						University of York